[net 2/3] can: isotp: fix msg_namelen values depending on CAN_REQUIRED_SIZE
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-03-29 08:55:47
Also in:
linux-can
Subsystem:
can network layer, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, Linus Torvalds
From: Oliver Hartkopp <socketcan@hartkopp.net>
Since commit f5223e9eee65 ("can: extend sockaddr_can to include j1939
members") the sockaddr_can has been extended in size and a new
CAN_REQUIRED_SIZE macro has been introduced to calculate the protocol
specific needed size.
The ABI for the msg_name and msg_namelen has not been adapted to the
new CAN_REQUIRED_SIZE macro for the other CAN protocols which leads to
a problem when an existing binary reads the (increased) struct
sockaddr_can in msg_name.
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Reported-by: Richard Weinberger <richard@nod.at>
Acked-by: Kurt Van Dijck <redacted>
Link: https://lore.kernel.org/linux-can/1135648123.112255.1616613706554.JavaMail.zimbra@nod.at/T/#t (local)
Link: https://lore.kernel.org/r/20210325125850.1620-2-socketcan@hartkopp.net (local)
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/isotp.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/can/isotp.c b/net/can/isotp.c
index 15ea1234d457..9f94ad3caee9 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c@@ -77,6 +77,8 @@ MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>"); MODULE_ALIAS("can-proto-6"); +#define ISOTP_MIN_NAMELEN CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp) + #define SINGLE_MASK(id) (((id) & CAN_EFF_FLAG) ? \ (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG))
@@ -986,7 +988,8 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size, sock_recv_timestamp(msg, sk, skb); if (msg->msg_name) { - msg->msg_namelen = sizeof(struct sockaddr_can); + __sockaddr_check_size(ISOTP_MIN_NAMELEN); + msg->msg_namelen = ISOTP_MIN_NAMELEN; memcpy(msg->msg_name, skb->cb, msg->msg_namelen); }
@@ -1056,7 +1059,7 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len) int notify_enetdown = 0; int do_rx_reg = 1; - if (len < CAN_REQUIRED_SIZE(struct sockaddr_can, can_addr.tp)) + if (len < ISOTP_MIN_NAMELEN) return -EINVAL; /* do not register frame reception for functional addressing */
@@ -1152,13 +1155,13 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer) if (peer) return -EOPNOTSUPP; - memset(addr, 0, sizeof(*addr)); + memset(addr, 0, ISOTP_MIN_NAMELEN); addr->can_family = AF_CAN; addr->can_ifindex = so->ifindex; addr->can_addr.tp.rx_id = so->rxid; addr->can_addr.tp.tx_id = so->txid; - return sizeof(*addr); + return ISOTP_MIN_NAMELEN; } static int isotp_setsockopt(struct socket *sock, int level, int optname,
--
2.30.2